Commit | Line | Data |
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76181c13 | 1 | /* Authentication token and access key management |
1da177e4 | 2 | * |
76181c13 | 3 | * Copyright (C) 2004, 2007 Red Hat, Inc. All Rights Reserved. |
1da177e4 LT |
4 | * Written by David Howells (dhowells@redhat.com) |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | * | |
11 | * | |
d410fa4e | 12 | * See Documentation/security/keys.txt for information on keys/keyrings. |
1da177e4 LT |
13 | */ |
14 | ||
15 | #ifndef _LINUX_KEY_H | |
16 | #define _LINUX_KEY_H | |
17 | ||
18 | #include <linux/types.h> | |
19 | #include <linux/list.h> | |
20 | #include <linux/rbtree.h> | |
76d8aeab | 21 | #include <linux/rcupdate.h> |
0b77f5bf | 22 | #include <linux/sysctl.h> |
aa84442d | 23 | #include <linux/rwsem.h> |
60063497 | 24 | #include <linux/atomic.h> |
b2a4df20 | 25 | #include <linux/assoc_array.h> |
1da177e4 LT |
26 | |
27 | #ifdef __KERNEL__ | |
9a56c2db | 28 | #include <linux/uidgid.h> |
1da177e4 LT |
29 | |
30 | /* key handle serial number */ | |
31 | typedef int32_t key_serial_t; | |
32 | ||
33 | /* key handle permissions mask */ | |
34 | typedef uint32_t key_perm_t; | |
35 | ||
36 | struct key; | |
37 | ||
38 | #ifdef CONFIG_KEYS | |
39 | ||
40 | #undef KEY_DEBUGGING | |
41 | ||
664cceb0 DH |
42 | #define KEY_POS_VIEW 0x01000000 /* possessor can view a key's attributes */ |
43 | #define KEY_POS_READ 0x02000000 /* possessor can read key payload / view keyring */ | |
44 | #define KEY_POS_WRITE 0x04000000 /* possessor can update key payload / add link to keyring */ | |
45 | #define KEY_POS_SEARCH 0x08000000 /* possessor can find a key in search / search a keyring */ | |
46 | #define KEY_POS_LINK 0x10000000 /* possessor can create a link to a key/keyring */ | |
29db9190 DH |
47 | #define KEY_POS_SETATTR 0x20000000 /* possessor can set key attributes */ |
48 | #define KEY_POS_ALL 0x3f000000 | |
664cceb0 DH |
49 | |
50 | #define KEY_USR_VIEW 0x00010000 /* user permissions... */ | |
51 | #define KEY_USR_READ 0x00020000 | |
52 | #define KEY_USR_WRITE 0x00040000 | |
53 | #define KEY_USR_SEARCH 0x00080000 | |
54 | #define KEY_USR_LINK 0x00100000 | |
29db9190 DH |
55 | #define KEY_USR_SETATTR 0x00200000 |
56 | #define KEY_USR_ALL 0x003f0000 | |
1da177e4 LT |
57 | |
58 | #define KEY_GRP_VIEW 0x00000100 /* group permissions... */ | |
59 | #define KEY_GRP_READ 0x00000200 | |
60 | #define KEY_GRP_WRITE 0x00000400 | |
61 | #define KEY_GRP_SEARCH 0x00000800 | |
62 | #define KEY_GRP_LINK 0x00001000 | |
29db9190 DH |
63 | #define KEY_GRP_SETATTR 0x00002000 |
64 | #define KEY_GRP_ALL 0x00003f00 | |
1da177e4 LT |
65 | |
66 | #define KEY_OTH_VIEW 0x00000001 /* third party permissions... */ | |
67 | #define KEY_OTH_READ 0x00000002 | |
68 | #define KEY_OTH_WRITE 0x00000004 | |
69 | #define KEY_OTH_SEARCH 0x00000008 | |
70 | #define KEY_OTH_LINK 0x00000010 | |
29db9190 DH |
71 | #define KEY_OTH_SETATTR 0x00000020 |
72 | #define KEY_OTH_ALL 0x0000003f | |
1da177e4 | 73 | |
6b79ccb5 AR |
74 | #define KEY_PERM_UNDEF 0xffffffff |
75 | ||
1da177e4 LT |
76 | struct seq_file; |
77 | struct user_struct; | |
78 | struct signal_struct; | |
d84f4f99 | 79 | struct cred; |
1da177e4 LT |
80 | |
81 | struct key_type; | |
82 | struct key_owner; | |
83 | struct keyring_list; | |
84 | struct keyring_name; | |
85 | ||
16feef43 DH |
86 | struct keyring_index_key { |
87 | struct key_type *type; | |
88 | const char *description; | |
89 | size_t desc_len; | |
90 | }; | |
91 | ||
664cceb0 DH |
92 | /*****************************************************************************/ |
93 | /* | |
94 | * key reference with possession attribute handling | |
95 | * | |
96 | * NOTE! key_ref_t is a typedef'd pointer to a type that is not actually | |
97 | * defined. This is because we abuse the bottom bit of the reference to carry a | |
98 | * flag to indicate whether the calling process possesses that key in one of | |
99 | * its keyrings. | |
100 | * | |
101 | * the key_ref_t has been made a separate type so that the compiler can reject | |
102 | * attempts to dereference it without proper conversion. | |
103 | * | |
104 | * the three functions are used to assemble and disassemble references | |
105 | */ | |
106 | typedef struct __key_reference_with_attributes *key_ref_t; | |
107 | ||
108 | static inline key_ref_t make_key_ref(const struct key *key, | |
a5b4bd28 | 109 | bool possession) |
664cceb0 DH |
110 | { |
111 | return (key_ref_t) ((unsigned long) key | possession); | |
112 | } | |
113 | ||
114 | static inline struct key *key_ref_to_ptr(const key_ref_t key_ref) | |
115 | { | |
116 | return (struct key *) ((unsigned long) key_ref & ~1UL); | |
117 | } | |
118 | ||
a5b4bd28 | 119 | static inline bool is_key_possessed(const key_ref_t key_ref) |
664cceb0 DH |
120 | { |
121 | return (unsigned long) key_ref & 1UL; | |
122 | } | |
123 | ||
1da177e4 LT |
124 | /*****************************************************************************/ |
125 | /* | |
126 | * authentication token / access credential / keyring | |
127 | * - types of key include: | |
128 | * - keyrings | |
129 | * - disk encryption IDs | |
130 | * - Kerberos TGTs and tickets | |
131 | */ | |
132 | struct key { | |
133 | atomic_t usage; /* number of references */ | |
134 | key_serial_t serial; /* key serial number */ | |
65d87fe6 DH |
135 | union { |
136 | struct list_head graveyard_link; | |
137 | struct rb_node serial_node; | |
138 | }; | |
1da177e4 LT |
139 | struct rw_semaphore sem; /* change vs change sem */ |
140 | struct key_user *user; /* owner of this key */ | |
29db9190 | 141 | void *security; /* security data for this key */ |
5d135440 DH |
142 | union { |
143 | time_t expiry; /* time at which key expires (or 0) */ | |
144 | time_t revoked_at; /* time at which key was revoked */ | |
145 | }; | |
31d5a79d | 146 | time_t last_used_at; /* last time used for LRU keyring discard */ |
9a56c2db EB |
147 | kuid_t uid; |
148 | kgid_t gid; | |
1da177e4 LT |
149 | key_perm_t perm; /* access permissions */ |
150 | unsigned short quotalen; /* length added to quota */ | |
76d8aeab DH |
151 | unsigned short datalen; /* payload data length |
152 | * - may not match RCU dereferenced payload | |
153 | * - payload should contain own length | |
154 | */ | |
1da177e4 LT |
155 | |
156 | #ifdef KEY_DEBUGGING | |
157 | unsigned magic; | |
158 | #define KEY_DEBUG_MAGIC 0x18273645u | |
159 | #define KEY_DEBUG_MAGIC_X 0xf8e9dacbu | |
160 | #endif | |
161 | ||
76d8aeab DH |
162 | unsigned long flags; /* status flags (change with bitops) */ |
163 | #define KEY_FLAG_INSTANTIATED 0 /* set if key has been instantiated */ | |
164 | #define KEY_FLAG_DEAD 1 /* set if key type has been deleted */ | |
165 | #define KEY_FLAG_REVOKED 2 /* set if key had been revoked */ | |
166 | #define KEY_FLAG_IN_QUOTA 3 /* set if key consumes quota */ | |
167 | #define KEY_FLAG_USER_CONSTRUCT 4 /* set if key is being constructed in userspace */ | |
168 | #define KEY_FLAG_NEGATIVE 5 /* set if key is negative */ | |
700920eb | 169 | #define KEY_FLAG_ROOT_CAN_CLEAR 6 /* set if key can be cleared by root without permission */ |
fd75815f | 170 | #define KEY_FLAG_INVALIDATED 7 /* set if key has been invalidated */ |
008643b8 DH |
171 | #define KEY_FLAG_TRUSTED 8 /* set if key is trusted */ |
172 | #define KEY_FLAG_TRUSTED_ONLY 9 /* set if keyring only accepts links to trusted keys */ | |
32c4741c | 173 | #define KEY_FLAG_BUILTIN 10 /* set if key is builtin */ |
0c7774ab | 174 | #define KEY_FLAG_ROOT_CAN_INVAL 11 /* set if key can be invalidated by root without permission */ |
76d8aeab | 175 | |
16feef43 DH |
176 | /* the key type and key description string |
177 | * - the desc is used to match a key against search criteria | |
178 | * - it should be a printable string | |
1da177e4 LT |
179 | * - eg: for krb5 AFS, this might be "afs@REDHAT.COM" |
180 | */ | |
16feef43 DH |
181 | union { |
182 | struct keyring_index_key index_key; | |
183 | struct { | |
184 | struct key_type *type; /* type of key */ | |
185 | char *description; | |
186 | }; | |
187 | }; | |
1da177e4 LT |
188 | |
189 | /* type specific data | |
190 | * - this is used by the keyring type to index the name | |
191 | */ | |
192 | union { | |
193 | struct list_head link; | |
7318226e DH |
194 | unsigned long x[2]; |
195 | void *p[2]; | |
fdd1b945 | 196 | int reject_error; |
1da177e4 LT |
197 | } type_data; |
198 | ||
199 | /* key data | |
200 | * - this is used to hold the data actually used in cryptography or | |
201 | * whatever | |
202 | */ | |
203 | union { | |
b2a4df20 DH |
204 | union { |
205 | unsigned long value; | |
206 | void __rcu *rcudata; | |
207 | void *data; | |
ab3c3587 | 208 | void *data2[2]; |
b2a4df20 DH |
209 | } payload; |
210 | struct assoc_array keys; | |
211 | }; | |
1da177e4 LT |
212 | }; |
213 | ||
1da177e4 LT |
214 | extern struct key *key_alloc(struct key_type *type, |
215 | const char *desc, | |
9a56c2db | 216 | kuid_t uid, kgid_t gid, |
d84f4f99 | 217 | const struct cred *cred, |
7e047ef5 DH |
218 | key_perm_t perm, |
219 | unsigned long flags); | |
220 | ||
221 | ||
222 | #define KEY_ALLOC_IN_QUOTA 0x0000 /* add to quota, reject if would overrun */ | |
223 | #define KEY_ALLOC_QUOTA_OVERRUN 0x0001 /* add to quota, permit even if overrun */ | |
224 | #define KEY_ALLOC_NOT_IN_QUOTA 0x0002 /* not in quota */ | |
008643b8 | 225 | #define KEY_ALLOC_TRUSTED 0x0004 /* Key should be flagged as trusted */ |
7e047ef5 | 226 | |
1da177e4 | 227 | extern void key_revoke(struct key *key); |
fd75815f | 228 | extern void key_invalidate(struct key *key); |
1da177e4 LT |
229 | extern void key_put(struct key *key); |
230 | ||
ccc3e6d9 | 231 | static inline struct key *__key_get(struct key *key) |
1da177e4 | 232 | { |
ccc3e6d9 | 233 | atomic_inc(&key->usage); |
1da177e4 LT |
234 | return key; |
235 | } | |
236 | ||
ccc3e6d9 DH |
237 | static inline struct key *key_get(struct key *key) |
238 | { | |
239 | return key ? __key_get(key) : key; | |
240 | } | |
241 | ||
664cceb0 DH |
242 | static inline void key_ref_put(key_ref_t key_ref) |
243 | { | |
244 | key_put(key_ref_to_ptr(key_ref)); | |
245 | } | |
246 | ||
1da177e4 LT |
247 | extern struct key *request_key(struct key_type *type, |
248 | const char *description, | |
249 | const char *callout_info); | |
250 | ||
4e54f085 DH |
251 | extern struct key *request_key_with_auxdata(struct key_type *type, |
252 | const char *description, | |
4a38e122 DH |
253 | const void *callout_info, |
254 | size_t callout_len, | |
4e54f085 DH |
255 | void *aux); |
256 | ||
76181c13 DH |
257 | extern struct key *request_key_async(struct key_type *type, |
258 | const char *description, | |
4a38e122 DH |
259 | const void *callout_info, |
260 | size_t callout_len); | |
76181c13 DH |
261 | |
262 | extern struct key *request_key_async_with_auxdata(struct key_type *type, | |
263 | const char *description, | |
4a38e122 DH |
264 | const void *callout_info, |
265 | size_t callout_len, | |
76181c13 DH |
266 | void *aux); |
267 | ||
268 | extern int wait_for_key_construction(struct key *key, bool intr); | |
269 | ||
b404aef7 | 270 | extern int key_validate(const struct key *key); |
1da177e4 | 271 | |
664cceb0 DH |
272 | extern key_ref_t key_create_or_update(key_ref_t keyring, |
273 | const char *type, | |
274 | const char *description, | |
275 | const void *payload, | |
276 | size_t plen, | |
6b79ccb5 | 277 | key_perm_t perm, |
7e047ef5 | 278 | unsigned long flags); |
1da177e4 | 279 | |
664cceb0 | 280 | extern int key_update(key_ref_t key, |
1da177e4 LT |
281 | const void *payload, |
282 | size_t plen); | |
283 | ||
284 | extern int key_link(struct key *keyring, | |
285 | struct key *key); | |
286 | ||
287 | extern int key_unlink(struct key *keyring, | |
288 | struct key *key); | |
289 | ||
9a56c2db | 290 | extern struct key *keyring_alloc(const char *description, kuid_t uid, kgid_t gid, |
d84f4f99 | 291 | const struct cred *cred, |
96b5c8fe | 292 | key_perm_t perm, |
7e047ef5 | 293 | unsigned long flags, |
d720024e | 294 | struct key *dest); |
1da177e4 LT |
295 | |
296 | extern int keyring_clear(struct key *keyring); | |
297 | ||
664cceb0 DH |
298 | extern key_ref_t keyring_search(key_ref_t keyring, |
299 | struct key_type *type, | |
300 | const char *description); | |
1da177e4 | 301 | |
1da177e4 LT |
302 | extern int keyring_add_key(struct key *keyring, |
303 | struct key *key); | |
304 | ||
305 | extern struct key *key_lookup(key_serial_t id); | |
306 | ||
456a8167 | 307 | static inline key_serial_t key_serial(const struct key *key) |
7249db2c DH |
308 | { |
309 | return key ? key->serial : 0; | |
310 | } | |
1da177e4 | 311 | |
59e6b9c1 BS |
312 | extern void key_set_timeout(struct key *, unsigned); |
313 | ||
f5895943 DH |
314 | /* |
315 | * The permissions required on a key that we're looking up. | |
316 | */ | |
317 | #define KEY_NEED_VIEW 0x01 /* Require permission to view attributes */ | |
318 | #define KEY_NEED_READ 0x02 /* Require permission to read content */ | |
319 | #define KEY_NEED_WRITE 0x04 /* Require permission to update / modify */ | |
320 | #define KEY_NEED_SEARCH 0x08 /* Require permission to search (keyring) or find (key) */ | |
321 | #define KEY_NEED_LINK 0x10 /* Require permission to link */ | |
322 | #define KEY_NEED_SETATTR 0x20 /* Require permission to change attributes */ | |
323 | #define KEY_NEED_ALL 0x3f /* All the above permissions */ | |
324 | ||
78b7280c DH |
325 | /** |
326 | * key_is_instantiated - Determine if a key has been positively instantiated | |
327 | * @key: The key to check. | |
328 | * | |
329 | * Return true if the specified key has been positively instantiated, false | |
330 | * otherwise. | |
331 | */ | |
332 | static inline bool key_is_instantiated(const struct key *key) | |
333 | { | |
334 | return test_bit(KEY_FLAG_INSTANTIATED, &key->flags) && | |
335 | !test_bit(KEY_FLAG_NEGATIVE, &key->flags); | |
336 | } | |
337 | ||
633e804e DH |
338 | #define rcu_dereference_key(KEY) \ |
339 | (rcu_dereference_protected((KEY)->payload.rcudata, \ | |
340 | rwsem_is_locked(&((struct key *)(KEY))->sem))) | |
341 | ||
ee0b31a2 | 342 | #define rcu_assign_keypointer(KEY, PAYLOAD) \ |
e5c1f444 PM |
343 | do { \ |
344 | rcu_assign_pointer((KEY)->payload.rcudata, (PAYLOAD)); \ | |
345 | } while (0) | |
ee0b31a2 | 346 | |
0b77f5bf | 347 | #ifdef CONFIG_SYSCTL |
d6f50c95 | 348 | extern struct ctl_table key_sysctls[]; |
0b77f5bf | 349 | #endif |
1da177e4 LT |
350 | /* |
351 | * the userspace interface | |
352 | */ | |
d84f4f99 | 353 | extern int install_thread_keyring_to_cred(struct cred *cred); |
1da177e4 LT |
354 | extern void key_fsuid_changed(struct task_struct *tsk); |
355 | extern void key_fsgid_changed(struct task_struct *tsk); | |
356 | extern void key_init(void); | |
357 | ||
358 | #else /* CONFIG_KEYS */ | |
359 | ||
360 | #define key_validate(k) 0 | |
361 | #define key_serial(k) 0 | |
7888e7ff | 362 | #define key_get(k) ({ NULL; }) |
0dab9cfa | 363 | #define key_revoke(k) do { } while(0) |
fd75815f | 364 | #define key_invalidate(k) do { } while(0) |
1da177e4 | 365 | #define key_put(k) do { } while(0) |
664cceb0 | 366 | #define key_ref_put(k) do { } while(0) |
8bbf4976 DH |
367 | #define make_key_ref(k, p) NULL |
368 | #define key_ref_to_ptr(k) NULL | |
664cceb0 | 369 | #define is_key_possessed(k) 0 |
1da177e4 LT |
370 | #define key_fsuid_changed(t) do { } while(0) |
371 | #define key_fsgid_changed(t) do { } while(0) | |
372 | #define key_init() do { } while(0) | |
373 | ||
374 | #endif /* CONFIG_KEYS */ | |
375 | #endif /* __KERNEL__ */ | |
376 | #endif /* _LINUX_KEY_H */ |